Dart rewrite (Nexus Tools 5)

[corbindavenport]

I'm currently in the process of rewriting Nexus Tools as a command-line application written in Dart. The current shell script version has become difficult to maintain, especially compensating for every possible variation of operating system, shell, and CPU architecture.

A version of Nexus Tools that functions similarly to the existing install.sh is already in the dart branch. To maintain compatibility with all the online guides and forum threads that include the web install command for Nexus Tools, the existing install.sh bash script will become a wrapper that downloads and executes the Dart file.

There are a few upsides to this approach:

• More features can be added
• The varying syntax for scripting across different shells won't cause weird bugs anymore
• Nexus Tools can download and unzip the Platform Tools package itself, instead of relying on the host's copies of curl and unzip
• Cleaner code
• Windows support

There are also a few downsides:

• Nexus Tools will have to be compiled for each platform, but since Google only provides x86 Platform Tools binaries, Nexus Tools only needs to support x86 macOS and x86 Linux right now.
• Dart CLI apps cannot be signed for macOS right now, so install.sh will have to include steps for bypassing the signing requirement on macOS. This isn't a problem: https://github.com/corbindavenport/nexus-tools/issues/58#issuecomment-912239273

The work that still needs to be done:

• [x] Add support for command-line arguments, with one for installing and one for uninstalling. When Nexus Tools is started without an argument, it should display a help message.
• [x] The install.sh and uninstall.sh scripts should download and execute Nexus Tools with the install and uninstall arguments, respectively.
• [x] Add support for the no-analytics argument already available in the current version, with pass-through support from the bash script installer (like running install.sh no-analytics right now).
• [x] Test and build Dart application and install.sh wrapper on macOS
• [x] Test and build for Windows
• [x] Nexus Tools executable should be installed to the same directory
• [x] Update the readme file with instructions for downloading and running Nexus Tools locally, in addition to the existing install.sh method.
• [x] Add update check
• [x] Add web install for Windows
• [x] Bug: The code for adding Nexus Tools to $PATH doesn't seem to make a new line.
• [x] Bug: Empty folder detected as fully installed

[corbindavenport]

Windows support is working!

[corbindavenport]

The rewritten version runs great on macOS, and at least with macOS Big Sur and older, the executable doesn't need to be signed! Tested on x86 Mojave and ARM Big Sur. Only issue is that analytics now reports ARM macOS as x86 macOS, because the uname -m check runs under the same Rosetta environment, but that's not a big deal.

[corbindavenport]

The Dart version is now live.